Tom, W8JI wrote:
"This is an important issue because the myth about shields is embedded
in amateur circles despite many clearly written engineering texts and
very simple experiments that prove the concept of time-varying magnetic
fields penetrating the shield."

Some of that poison reached the 2006 ARRL Handbook on page 13.18. Fig
13.26 says:
"Electrostatically-shielded loop for RDF. To prevent shielding of the
loop from magnetic fields, leave the shield unconnected at one end."

Terman`s RDF loop should have better balance than ARRL`s because
Terman`s shield gap is squarely in the center of the loop
and not at one end. However, as long as the shield is broken preventing
induced current from flowing around the shield, Lenz`s law will be
thwarted and magnetic coupling to the coil under the shield will be
obtained. Electric field coupling to the coil beneath the shield will be
disallowed by the shield`s connection to ground wherever it occurs,
though not as elegantly as when care is taken to get the best balance
possible.

I`ve worked with such Faraday screens in my broadcasting career.

Best regards, Richard Harrison, KB5WZI